• Title/Summary/Keyword: Bypass Technique

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Optimal Design of PV Module with Bypass Diode to Reduce Degradation due to Reverse Excess Current

  • Jung, Tae-Hee;Kang, Gi-Hwan;Ahn, Hyung-Keun
    • Transactions on Electrical and Electronic Materials
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    • v.15 no.5
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    • pp.279-283
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    • 2014
  • In this paper, we present an economical and practical standard to install a bypass diode in a thin-film PV module. This method helps to reduce heat generation and to prevent module degradation due to excess current from reverse bias. The experimental results confirm that for different numbers of solar cells, there is a relation between the excess reverse current and the degradation of solar cells in a-Si:H modules. The optimal number of solar cells that can be connected per bypass diode could be obtained through an analysis of the results to effectively suppress the degradation and to reduce the heat generated by the module. This technique could be expanded for use in high power crystalline Si PV modules.

In Situ Rescue Bypass for Iatrogenic Avulsion of Parent Artery during Clipping Large Pericallosal Artery Aneurysm

  • Park, Jae-Chan;Kang, Dong-Hun
    • Journal of Korean Neurosurgical Society
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    • v.46 no.1
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    • pp.68-70
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    • 2009
  • A case of large aneurysm arising from the distal end of an azygous A2 segment is presented. Multiple clip application inadvertently tore the aneurysmal neck, resulting in near avulsion of a right pericallosal artery origin. After an unsuccessful attempt to repair the avulsion, it was treated by occlusion of the origin of the pericallosal artery and an A4-A4 anterior cerebral artery in situ bypass without neurological deficits. The surgical technique and previous reports onside-to-side in situ bypass are discussed.

Repair of intracardiac defect under simple deep hypothermia in infancy without cardiopulmonary bypass: report of 3 cases (단순 초저온법에 의한 개심술: 3례 보)

  • 조범구
    • Journal of Chest Surgery
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    • v.17 no.2
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    • pp.189-196
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    • 1984
  • Although the conventional methods of cardiopulmonary bypass for open heart surgery have been employed, it has been usual method to repair of congenital heart disease in infancy using deep hypother-mia and circulatory arrest technique. In 1980, we reported total correction of congenital heart disease using surface induced hypothermia-total circulatory arrest and rewarming with limited cardiopulmonary bypass. in 1981, three patients below 10 kilogram, who had ASD and PDA, and two of VSD with pulmonary hypertension were operated on using simple deep hypothermia without cardiopulmonary bypass. During surface cooling, there were no ventricular fibrillation and arrhythmia. There were no difficulties to resuscitate the heart. Postoperative respiratory and neurologic complication were not occurred. Follow up examination for two to three years gave no evidence of cerebral damage due to circulatory arrest.

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In Situ Saphenous Vein Arterial Bypass - A case report - (자연위치의 복재정맥을 이용한 하지동맥 우회술 1례 보)

  • Lee, Hong-Seop;Park, Guk-Yang;Kim, Chang-Ho
    • Journal of Chest Surgery
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    • v.20 no.1
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    • pp.187-190
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    • 1987
  • The Saphenous vein is still the graft of choice for bypass of small calibered peripheral arteries, and many recent studies revealed that the "In Situ" technique had higher rate of long term patency than the conventional "reversed" one. A 71-year-old male who had atherosclerotic obstruction in the superficial femoral and popliteal trifurcation underwent In Situ saphenous vein arterial bypass. The saphenous vein is exposed by a long medial skin incision over the course of the vein. All branches of vein are ligated. A olive-tipped metal needle is introduced into the vein from above and everts the valves. The patient has been followed for 2 months after operation. The graft remained pulsatile and the gangrenous areas on the toe proceeded to heal. We think In situ vein bypass offers an excellent and safe method of revascularization of the arterial occlusion below the knee although it is technically demanding and the time consuming. time consuming.

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Coronary Artery Bypass Grafti ng without Extracorporeal Ci rculation One Case Report (체외순환을 사용하지 않은 관상동맥우회술-1례보고-)

  • 임창영;이헌재
    • Journal of Chest Surgery
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    • v.30 no.3
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    • pp.326-329
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    • 1997
  • Coronary artery bypass grafting(CABG) without cardiopulmonary bypass(CPB) is now an accepted technique of myocardial revascularization in selective cases of coronary arterial occlusive disease. The lesion was total(100%) occlusion of proximal right coronary artery(RCA) without any evidence of dis,Base in the rest of coronary arteries. Percutaneous transluminal angioplasty(PTCA) was tried but unsuccessful. We herein report a case of successful CABG to right coronary artery without CPB on a patient with complete occlusion of RCA and symptomatic wit minimal activity.

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Tracheal Reconstruction Using Femoro-Femoral Bypass -A Case Report- (우측 소매 전폐 적출술 후 발생한 기관 협착증의 체외 순환을 이용한 수술치험 1례)

  • 최필조
    • Journal of Chest Surgery
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    • v.27 no.4
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    • pp.324-327
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    • 1994
  • Resection and reconstruction of distal trachea or carina have posed tremendous technical challenges for surgeons. Successful outcome depends on thorough preoperative evaluation, careful anesthetic management,strict attention of surgical technique and postoperative care. We report a successful case of revision of tracheal stenosis using femoro-femoral bypass on a 13~year-old boy. The patient complained severe dyspnea about I month following right sleeve pneumonectomy. Preoperative CT scan and intraoperative bronchoscopy showed pin-point tracheal stenosis at a tracheo-bronchial anastomosis site about 1.2cm in length.At operation the lesion was severely adhesed and the lumen was nearly obstructed. The stenotic segment was resected and direct end-to-end anastomosis was done under femoro-femoral bypass for adequate oxygenation. The patient was discharged at postop. 16 days without specific complications and has continued to do well.

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Application of the New Surgical Technique for Orthotopic Heart Transplantation in Dogs (잡견에 있어서 새로운 심장수술기법의 적용)

  • 원태희;한재진;김기봉;노준량
    • Journal of Chest Surgery
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    • v.33 no.3
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    • pp.207-211
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    • 2000
  • Backgroud: Conventional cardiac transplantation with each atrial anastomosis designed by Shumway and associates has been used widely in cardiac transplantation because of its simplicity and efficiency. There have been many reports about the postoperative atrioventricular value regurgitation resulting from the alteration in atrial geometry after cardiac transplantation by Shumway's technique. New surgical technique of direct anastomosis of superior vena cava, inferior vena cava, right pulmonary vein and left pulmonary vein was introduced to overcome the those problems. We performed this study to test the feasibility of this new surgical technique prior to application to clinical practice. Material and Method: Conventional cardiac transplantation was performed on 12 mongrel dogs(Group I) and cardiac transplantation with new surgical mthod of direct anastomosis of SVC, IVC, left and right pulmonary veins was performed on 11 mongrel dogs(Group II). After weaning from cardiopulmonary bypass, we compared the postoperative rhythm, hemodynamic data, and echocardiographic findings between two groups. Result : The cardiopulmonary bypass time and graft ischemic time were 119.0$\pm$4.4 minutes, 162.0$\pm$4.5 minutes respectively in group I, and 140.0$\pm$7.1 minutes, 180.5$\pm$5.4 minutes respectively in group II. The cardiopulmonary time and graft ischemic time in group II were longer than those of group I (p<0.05). There were 3 cases of failure to weaning from cardipulmonary bypass onein group I and two in group II, and this difference was not significant statistically. Sinus rhythm was regained postoperatively in 58% (group I) and 82%(group II), without statistical significant between 2 groups. Postoperative echolcardiography showed 2 cases of tricuspid value regurgitation and 1 case of mitral regurgitation in group I, and no regurgitation of atrioventricular value in group II. Conclusion: Although these was no statistically significant difference between 2 groups, there was tendency of less arrhythmia and less atrioventricular valvular regurgitation in group II. We suggested that the new surgical technique could be a useful strategy in heart transplantation, especially in the case of size mismatching between donor and recipient.

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Effects of Protein Bypass Treatments in Oilseed Meals on Availability of Mineral in Sheep (박류의 단백질 Bypass 처리가 면양의 광물질 이용효율에 미치는 영향)

  • Park, Woong-Yeoul
    • Korean Journal of Organic Agriculture
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    • v.16 no.3
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    • pp.331-339
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    • 2008
  • The effects of heat and formaldehyde treatments of soybean meal and rapeseed meal on ruminal release of minerals from the meals were studied on three sheep fitted with rumen cannula. Oilseed meals were treated at 133, $143^{\circ}C$ for 3h or added with formaldehyde at a level of 3, 5g/kg. The ruminal release of P, Ca, Mg, Cu, Fe and Zn from the oilseed meals was examined using the nylon bag technique. Effective degradabilities of minerals in the oilseed meals were reduced by both treatments. The results suggest that rumen bypass treatments of oilseed meals prevent the release of minerals from the meals during rumen digestion and suppress the availability of mineals for ruminants. Eventually, the increase of heavy metal pollution in soil is anticipated due to the increase of mineral content in the feces of ruminants by ruminal protein bypass treatments.

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Simple Anastomotic Techniques for Coronary Artery Bypass Surgery in Patients with Small Coronary Arteries or a Marked Size Discrepancy Between the Coronary Artery and Graft

  • Lee, Mi Kyung;Song, Joon Young;Kim, Tae Youn;Kim, Jong Hun;Choi, Jong Bum;Kuh, Ja Hong
    • Journal of Chest Surgery
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    • v.49 no.6
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    • pp.485-488
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    • 2016
  • Different suture techniques have been used for anastomosis in coronary artery bypass graft surgery. Bypass surgery may be difficult for patients who have small coronary arteries or marked size discrepancies between target coronary arteries and grafts. For proximal and distal anastomoses, three continuous stitches are first placed in the heel and toe of the small coronary arteries; for sequential anastomosis, an interrupted eight-stitch technique is used. We applied these anastomotic suture techniques in patients requiring coronary artery bypass graft surgery, achieving an early angiographic patency rate of 100%.

Sterile Necrosis of the Sternum: A Rare Complication Following Coronary Artery Bypass Surgery

  • Papadakis, Emmanouel;Konstantinidou, Maria Kalliopi;Kanakis, Meletios A.
    • Journal of Chest Surgery
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    • v.50 no.6
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    • pp.460-462
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    • 2017
  • We herein present the unique case of a 68-year-old male diabetic patient who developed sterile necrosis of the sternum 1 month after myocardial revascularization with the use of bilateral internal thoracic artery grafts. The sternum had been closed by the bilateral Robicsek wiring technique. The sternum was removed, and bilateral pectoralis major flaps were used to cover the defect. The patient had an uneventful recovery.